Formed three-dimensional matrix and associated coating providing modulated release of volatile compositions

ABSTRACT

Described are bonding modulating coatings configured to provide an improved release profile of a volatile composition from a scent reservoir, wherein the modulating coating includes a barrier substance configured to hinder the release of the volatile composition through the modulating coating. The modulating coating also includes a hygroscopic substance that facilitates the release of the volatile composition through the modulating coating. The barrier substance and hygroscopic substance are mixed in a proportion such that the modulating coating provides a bonding action between adjacent scent reservoirs and may be formulated to maintain bonding even under the application of heat. The bonding modulating coating may then be used to bond a number of scent reservoirs together into a larger, three-dimensional matrix to provide improved scent retention and longevity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/173,264, filed Jun. 9, 2015, the entirety of which is incorporatedherein by reference.

FIELD OF THE INVENTION

The field of the invention relates to articles that provide modulatedrelease of volatile compositions, and more specifically relate toarticles that provide a modulated release of volatile olfactory orfragrance compounds.

BACKGROUND

Fragrance-releasing devices are well known and commonly used inhousehold and commercial establishments to provide a pleasantenvironment for people in the immediate space. Further, aroma-drivenexperiences are well recognized to improve or enhance the general moodof individuals. In some instances, fragrances may trigger memories ofexperiences associated with the specific scent. Whether it is providinga pleasant environment, affecting a general demeanor, or triggering anostalgic memory, a steady, long-lasting release of fragrance willensure consumer and customer satisfaction.

Fragrance-release devices based on passive diffusion are limited intheir product-use by a finite supply of the fragrance and itsevaporation rate from a surface. In some examples, the fragrance-releasedevice is designed to carry the fragrance liquid within its architectureso that the fragrance supply is finite and determined by the size of thefragrance-release device.

The evaporation rate of fragrance from the fragrance-release device isdetermined, at least in part, by the composition of the fragrance, wherecompositions containing more volatile compounds (e.g. “top” notes) willevaporate faster than those with less volatile compounds (e.g. “base”notes), and the temperature of the fragrance-release device. A fragrancecomposition determines its character. As a result, changing thecomposition of the fragrance may affect the character. The release rateprofile of fragrance is generally strong (more intense) at the beginningof product use, followed by decreasing intensity over time. In someinstances, the initial fragrance release is too strong and the fragrancerelease time is too short. For these fragrances, there is a need tomodulate the release of fragrance from the fragrance-release device toprovide a steady and long-lasting fragrance release without changing thefragrance load and character.

One method of enhancing the transfer of scent from a fragrance-releasedevice into the surrounding environment is to apply heat. Heat may serveto increase the evaporation rate of volatile compounds from afragrance-release device, especially in the later stages of use whenlower levels of fragrance remain. Heating a fragrance-release device mayalso provide more complete release of fragrance by fully vaporizing anyremaining volatile compounds at a rate that is still detectable by aperson in the vicinity of the device. However, heating afragrance-release device may lead to degradation or disintegration ofthe fragrance-release device. Also, without proper control over the rateof scent release, heating a fragrance-release device may lead toundesirably strong scents or early depletion of the fragrance reservoir.

Specifically there is a need to temper the release of fragrancecompounds in heated fragrance-release devices. A fragrance-releasedevice must not only control the release of scent into the surroundingenvironment, but also resist deterioration and disintegration underthermal stress.

SUMMARY

The terms “invention,” “the invention,” “this invention” and “thepresent invention” used in this patent are intended to refer broadly toall of the subject matter of this patent and the patent claims below.Statements containing these terms should be understood not to limit thesubject matter described herein or to limit the meaning or scope of thepatent claims below. Embodiments of the invention covered by this patentare defined by the claims below, not this summary. This summary is ahigh-level overview of various aspects of the invention and introducessome of the concepts that are further described in the DetailedDescription section below. This summary is not intended to identify keyor essential features of the claimed subject matter, nor is it intendedto be used in isolation to determine the scope of the claimed subjectmatter. The subject matter should be understood by reference toappropriate portions of the entire specification of this patent, any orall drawings and each claim.

According to certain embodiments of the present invention, a bondingmodulating coating may be configured to provide an improved releaseprofile of a volatile composition from a scent reservoir. The bondingmodulating coating comprises a barrier substance configured to hinder arelease of the volatile composition through the bonding modulatingcoating and a hygroscopic substance configured to facilitate the releaseof the volatile composition through the bonding modulating coating. Thebarrier substance and the hygroscopic substance may be mixed inproportion to provide bonding between adjacent scent reservoirs.

In certain embodiments, the hygroscopic substance may be configured tofacilitate the release of the volatile composition through the bondingmodulating coating by attracting water molecules into the bondingmodulating coating to displace the volatile composition trapped by thebarrier substance within the bonding modulating coating.

In some embodiments, the hygroscopic substance may comprise a silicasuspension.

In certain embodiments, the barrier substance may comprise a liquidstarch.

In some embodiments, the bonding modulating coating may be configured toresist temperatures higher than ambient. The bonding modulating coatingmay be configured to resist direct heating.

In certain embodiments, the wet weight ratio of the barrier substance tothe hygroscopic substance may be approximately 25:75. The wet ratio ofthe barrier substance to the hygroscopic substance may also beapproximately 75:25.

In some embodiments, the bonding modulating coating may compriseapproximately 45 to 60 percent barrier substance by wet weight. Infurther embodiments, the bonding modulating coating may comprise 40 to55 percent hygroscopic substance by wet weight.

In certain embodiments, a wet weight ratio of the barrier substance tothe hygroscopic substance may be approximately 55:45.

In some embodiments, a particle size of the hygroscopic substance mayrange from 0.001 μm-1 μm.

According to certain embodiments of the present invention, an aggregatearticle may comprise a plurality of scent reservoirs that may comprisean internal structure, a volatile composition, wherein at least some ofthe volatile composition may be located in the internal structure, and amodulating coating substantially covering at least one of the pluralityof scent reservoirs, wherein the modulating coating comprises a barriersubstance and a hygroscopic substance. The modulating coating may beconfigured to bond the plurality of scent reservoirs into athree-dimensional matrix.

In some embodiments, the hygroscopic substance may comprise a silicasuspension. In further embodiments, the barrier substance may comprise aliquid starch.

In certain embodiments, the modulating coating may be configured toresist temperatures higher than ambient. The modulating coating may beconfigured to resist direct heating.

In some embodiments, a wet weight ratio of the barrier substance to thehygroscopic substance may be approximately 25:75. In furtherembodiments, a wet weight ratio of the barrier substance to thehygroscopic substance may be 75:25.

In certain embodiments, the modulating coating may compriseapproximately 45 to 60 percent barrier substance by wet weight. Infurther embodiments, the modulating coating may comprise approximately40 to 55 percent hygroscopic substance by wet weight.

In some embodiments, a wet weight ratio of the barrier substance to thehygroscopic substance may be approximately 55:45.

In certain embodiments, a particle size of the hygroscopic substance mayrange from 0.001 μm-1 μm.

In some embodiments, the plurality of scent reservoirs may comprise atleast one scent reservoir selected from the group consisting of woundpaper, extruded pulp, wood chips, fiber bundles, and ceramic chunks.

In certain embodiments, at least some of the volatile composition may belocated within the modulating coating, wherein the modulating coatingfurther comprises water that is absorbed or adsorbed to the hygroscopicsubstance.

According to certain embodiments of the present invention, an aggregatearticle may comprise a plurality of scent reservoirs that may comprisean internal structure that may comprise pores, a volatile composition,wherein at least some of the volatile composition may be located in thepores, and a modulating coating distributed on exteriors surfaces of theplurality of scent reservoirs. The modulating coating may be formulatedto provide a heat resistant bond between the plurality of scentreservoirs, and the modulating coating may regulate the release rate ofthe volatile composition located in the pores.

According to certain embodiments of the present invention, a method formaking an aggregate article may comprise coating a plurality of scentreservoirs with a bonding modulating coating, depositing the pluralityof scent reservoirs within a perforated mold, compacting the pluralityof scent reservoirs within the perforated mold, drying the plurality ofscent reservoirs within the perforated mold, and releasing the pluralityof scent reservoirs from the perforated mold.

In some embodiments, the plurality of scent reservoirs may be infusedwith a volatile composition after coating. In further embodiments, theplurality of scent reservoirs may be dyed prior to coating.

In certain embodiments, the plurality of scent reservoirs may be infusedwith a volatile composition after releasing the plurality of scentreservoirs from the perforated mold.

In some embodiments, infusing the plurality of scent reservoirs with thevolatile composition comprises at least one of adding the volatilecomposition with a dropper, dipping the plurality of scent reservoirsinto the volatile composition, running the plurality of scent reservoirsthrough a volatile composition curtain, or infusing the volatilecomposition under a vacuum.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed description, embodiments of the invention aredescribed referring to the following figures:

FIG. 1 is a schematic illustrating the movement of a volatilecomposition across an internal structure of a base material and amodulating coating over time, according to certain embodiments of thepresent invention.

FIG. 2 is a cross-sectional view of an article formed from a pluralityof scent reservoirs compacted into an aggregate fragrance-releasedevice, according to certain embodiments of the present invention.

FIG. 2A is an enlarged view of the matrix composition of thefragrance-release device of FIG. 2.

FIG. 3 is a perspective view of a spherical aggregate fragrance-releasedevice.

FIG. 4 is a perspective view of a pyramidal aggregate fragrance-releasedevice.

FIG. 5 is a perspective view of a heart-shaped aggregatefragrance-release device.

FIG. 6 is a perspective view of tree-shaped aggregate fragrance-releasedevice.

FIG. 7 is a perspective view of a columnar aggregate fragrance-releasedevice.

FIG. 8 is a perspective view of toroidal and cubic aggregate fragrancerelease devices.

FIG. 9 is a graph showing a comparison of the cumulative amount releasedover time of a fragrance loaded in an aggregate fragrance-release deviceand loose scent reservoirs in both heated and ambient conditions.

FIG. 10 is a graph showing a comparison of the hedonic impact and thecumulative amount released over time of a fragrance loaded in anaggregate fragrance-release device and loose scent reservoirs in bothheated and ambient conditions.

FIG. 11 is a graph showing a comparison of the cumulative amountreleased of a fragrance for different geometries of aggregatefragrance-release devices and loose scent reservoirs in a heatedcondition.

DETAILED DESCRIPTION

The subject matter of embodiments of the present invention is describedhere with specificity to meet statutory requirements, but thisdescription is not necessarily intended to limit the scope of theclaims. The claimed subject matter may be embodied in other ways, mayinclude different elements or steps, and may be used in conjunction withother existing or future technologies. This description should not beinterpreted as implying any particular order or arrangement among orbetween various steps or elements except when the order of individualsteps or arrangement of elements is explicitly described.

According to certain embodiments of the present invention shown in FIG.1, an article comprises a base material 12 and a modulating coating 14.The base material 12 may comprise an internal structure 20 comprising aplurality of pores 22 that are configured to provide locations for thevolatile composition 24 to be stored therein and released therefrom,which is described in detail below. The modulating coating 14 mayprovide a structural function in addition to modulating the release of afragrance or other volatile compound contained within the pores 22 ofthe internal structure 20 of the base material 12. For example, themodulating coating 14 may be used to bond a number of individualarticles together to form an aggregate structure. In some embodiments,the modulating coating 14 may be specifically formulated to resist theapplication of heat or higher than ambient temperatures, such as whenthe article is placed on a warmer.

As used herein, “coating” refers to any composition that can be appliedusing any suitable method to at least one of an outer surface of athree-dimensional article, to some or all surfaces of a base material12, and/or may be uniformly or non-uniformly mixed throughout theinternal structure 20 of the base material 12 and/or the article. Incases of surface application, the coating may be applied so that thecomposition may or may not penetrate to at least some degree within thearticle and/or the base material 12.

The base material 12 may comprise natural and/or synthetic pulpcompositions; pulp compositions combined with other products, includingbut not limited to paper, cellulose, cellulose acetate, pulp lap, cottonlinters, biological plant-derived materials (from living plants),synthesized pulp compositions, and mixed pulps; polymer material; porousmaterial; and/or extrudate.

As known in the art, pulp is primarily a collection of fibers with othercomponents of the source material, wherein the fibers are derived from anatural or synthetic source material, for example, biological plants(natural) or petroleum-based synthesis products (synthetic). Pulp may beproduced from various types of woods using any one of several knownpulping techniques. The pulp may be from hardwoods, softwoods, ormixtures thereof. The pulp may also be made from recycled materials, andcomprises recovering waste paper and remaking it into new products.

In certain embodiments, the number and/or size of the plurality of pores22 (i.e., porosity) within the base material 12 may be controlled by thecompactness and/or size of the fibers and/or particles that form theinternal structure 20. For example, in certain embodiments of the basematerial 12 that comprise fibers, voids between the fibers form tiny airpassages throughout the internal structure 20. The compactness of thefibers affects the degree in which the base material 12 allows gas orliquid to pass through it. For example, porosity may affect uptake orload amount of volatile compositions, or may affect the rate of releaseof such substances. Porosity of the base material 12 may be affected byadding other materials, such as additives to the base material 12 as itis being formed from a composition, such as pulp or any othercomposition described above, so that the additives are located withinthe internal structure 20 of the base material 12 after formation.

The porosity of a base material 12 that comprises pulp may be affectedat any stage of the pulp production process. An increased level of fiberrefining causes the fibers to bond together more strongly and tightly,making the pulp material denser, thereby reducing the network of airpassages and the porosity. Surface sizing, coating, calendering orsupercalendering may also seal and/or further compress surface fibers.

The porosity of the base material 12 is measured quantitatively aseither the length of time it takes for a quantity of air to pass througha sample, or the rate of the passage of air through a sample, usingeither a Gurley densometer (in the first case) or a Sheffieldporosimeter (in the second case). With the Gurley densometer, theporosity is measured as the number of seconds required for 100 cubiccentimeters of air to pass through 1.0 square inch of a given materialat a pressure differential of 4.88 inches of water, as described in ISO5646-5, TAPPI T-460, or TAPPI T-536.

The porosity may affect how completely and how quickly the volatilecomposition 24 is absorbed into a pulp base material 12, as suchabsorption may occur primarily by capillary action. For example, a pulpbase material 12 with high porosity may have increased absorbency of thevolatile composition 24. The porosity of the pulp base material 12 mayrange from 0.01 Gurley second-100 Gurley seconds, and all rangestherein. In certain embodiments where there are multiple layers of pulpbase material 12, the porosity may range from 0.01 Gurley second-20Gurley seconds. The volatile composition 24 may be applied to the basematerial 12 in the form of a film, or a coating, or a treatmentintegrated into the internal structure 20 of the base material 12.

The volatile composition 24 may include but is not limited tofragrances, flavor compounds, odor-eliminating compounds, aromatherapycompounds, natural oils, water-based scents, odor neutralizingcompounds, and outdoor products (e.g., insect repellent).

As used herein, “volatile substance” refers to any compound, mixture, orsuspension of compounds that are odorous, or compound, mixture, orsuspension of compounds that cancel or neutralize odorous compounds,such as any compound or combination of compounds that would produce apositive or negative olfactory sense response in a living being that iscapable of responding to olfactory compounds, or that reduces oreliminates such olfactory responses.

A volatile composition as used herein comprises one or more volatilesubstances and is generally a composition that has a smell or odor,which may be volatile, which may be transported to the olfactory systemof a human or animal, and is generally provided in a sufficiently highconcentration so that it will interact with one or more olfactoryreceptors.

A fragrance may comprise an aroma or odorous compound, mixture orsuspension of compounds that is capable of producing an olfactoryresponse in a living being capable of responding to olfactory compounds,and may be referred to herein as odorant, aroma, scent, or fragrance. Afragrance composition may include one or more than one of the fragrancecharacteristics, including top notes, mid notes or heart, and the drydown or base notes. The volatile composition 24 may comprise otherdiluents or additives, such as solvents or preservatives.

Examples of volatile compositions 24 useful in the present inventioninclude but are not limited to, esters, terpenes, cyclic terpenes,phenolics, which are also referred to as aromatics, amines and alcohols.For example, furaneol 1-hexanol, cis-3-Hexen-1-ol, menthol,acetaldehyde, hexanal, cis-3-hexenal, furfural, fructone, hexyl acetate,ethyl methylphenylglycidate, dihydrojasmone, wine lactone,oct-1-en-3-one, 2-Acetyl-1-pyrroline,6-acetyl-2,3,4,5-tetrahydropyridine, gamma-decalactone,gamma-nonalactone, delta-octalactone, jasmine, massoia lactone, sotolonethanethiol, grapefruit mercaptan, methanethiol,2-methyl-2-propanethiol, methylphosphine, dimethylphosphine, methylformate, nerolin tetrahydrothiophene, 2,4,6-trichloroanisole,substituted pyrazines, methyl acetate, methyl butyrate, methylbutanoate, ethyl acetate, ethyl butyrate, ethyl butanoate, isoamylacetate, pentyl butyrate, pentyl butanoate, pentyl pentanoate, isoamylacetate, octyl acetate, myrcene, geraniol, nerol, citral, lemonal,geranial, neral, citronellal, citronellol, linalool, nerolidol,limonene, camphor, terpineol, alpha-ionone, terpineol, thujone,benzaldehyde, eugenol, cinnamaldehyde, ethyl maltol, vanillin, anisole,anethole, estragole, thymoltrimethylamine, putrescine, diaminobutane,cadaverine, pyridine, indole and skatole. Most of these are organiccompounds and are readily soluble in organic solvents, such as alcoholsor oils. Fragrance includes pure fragrances such as those includingessential oils and are known to those skilled in the art. Water-basedodorous compounds and other odorous compositions are also contemplatedby the present invention.

Fragrance oils as olfactory-active compounds or compositions usuallycomprise many different perfume raw materials. Each perfume raw materialused differs from another by several important properties includingindividual character and volatility. By bearing in mind these differentproperties, and others, the perfume raw material can be blended todevelop a fragrance oil with an overall specific character profile. Todate, characters are designed to alter and develop with time as thedifferent perfume raw materials evaporate from the substrate and aredetected by the user. For example, perfume raw materials that have ahigh volatility and low substantivity are commonly used to give aninitial burst of characters such as light, fresh, fruity, citrus, greenor delicate floral to the fragrance oil, which are detected soon afterapplication. Such materials are commonly referred to in the field offragrances as “top notes.” By way of a contrast, the less volatile, andmore substantive, perfume raw materials are typically used to givecharacters such as musk, sweet, balsamic, spicy, woody or heavy floralto the fragrance oil which, although may also be detected soon afterapplication, also last far longer. These materials are commonly referredto as “middle notes” or “base notes.” Highly skilled perfumers areusually employed to carefully blend perfume raw materials so that theresultant fragrance oils have the desired overall fragrance characterprofile. The desired overall character is dependent both upon the typeof composition in which the fragrance oil will finally be used and alsothe consumer preference for a fragrance.

In addition to the volatility, another important characteristic of aperfume raw material is its olfactory detection level, otherwise knownas the odor detection threshold (ODT). If a perfume raw material has alow odor detection threshold, only very low levels are required in thegas phase, or air, for it to be detected by the human, sometimes as lowas a few parts per billion. Conversely, if a perfume raw material has ahigh ODT, larger amounts or higher concentrations in the air of thatmaterial are required before it can be smelled by the user. The impactof a material is its function of its gas phase or air concentration andits ODT. Thus, volatile materials, capable of delivering large gas-phaseconcentrations, which also have low ODTs, are considered to beimpactful. To date, when developing a fragrance oil, it has beenimportant to balance the fragrance with both low and high volatility rawmaterials since the use of too many high volatility materials could leadto a short lived, overwhelming scent. As such the levels of high odorimpact perfume raw materials within a fragrance oil have traditionallybeen restricted.

As used herein the term “fragrance oil” relates to a perfume rawmaterial, or mixture of perfume raw materials, that are used to impartan overall pleasant odor profile to a composition, preferably a cosmeticcomposition. As used herein the term “perfume raw material” relates toany chemical compound that is odorous when in an un-entrapped state, forexample in the case of pro-perfumes, the perfume component is consideredto be a perfume raw material, and the pro-chemistry anchor is consideredto be the entrapment material. In addition “perfume raw materials” aredefined by materials with a ClogP value preferably greater than about0.1, more preferably greater than about 0.5, even more preferablygreater than about 1.0. As used herein the term “ClogP” means thelogarithm to base 10 of the octanol/water partition coefficient. Thiscan be readily calculated from a program called “CLOGP,” which isavailable from Daylight Chemical Information Systems Inc., IrvineCalif., USA. Octanol/water partition coefficients are described in moredetail in U.S. Pat. No. 5,578,563.

Examples of residual “middle and base note” perfume raw materialsinclude, but are not limited to, ethyl methyl phenyl glycidate, ethylvanillin, heliotropin, indol, methyl anthranilate, vanillin, amylsalicylate, coumarin. Further examples of residual perfume raw materialsinclude, but are not limited to, ambrox, bacdanol, benzyl salicylate,butyl anthranilate, cetalox, ebanol, cis-3-hexenyl salicylate, lilial,gamma undecalactone, gamma dodecalactone, gamma decalactone, calone,cymal, dihydro iso jasmonate, iso eugenol, lyral, methyl beta naphthylketone, beta naphthol methyl ether, para hydroxylphenyl butanone,8-cyclohexadecen-1-one, oxocyclohexadecen-2-one/habanolide, florhydral,intreleven aldehyde.

Examples of volatile “top note” perfume raw materials include, but arenot limited to, anethol, methyl heptine carbonate, ethyl aceto acetate,para cymene, nerol, decyl aldehyde, para cresol, methyl phenyl carbinylacetate, ionone alpha, ionone beta, undecylenic aldehyde, undecylaldehyde, 2,6-nonadienal, nonyl aldehyde, octyl aldehyde. Furtherexamples of volatile perfume raw materials include, but are not limitedto, phenyl acetaldehyde, anisic aldehyde, benzyl acetone, ethyl-2-methylbutyrate, damascenone, damascone alpha, damascone beta, flor acetate,frutene, fructone, herbavert, iso cyclo citral, methyl isobutenyltetrahydro pyran, isopropyl quinoline, 2,6-nonadien-1-ol,2-methoxy-3-(2-methylpropyl)-pyrazine, methyl octine carbonate,tridecene-2-nitrile, allyl amyl glycolate, cyclogalbanate, cyclal C,melonal, gamma nonalactone, c is 1,3-oxathiane-2-methyl-4-propyl.

Other useful residual “middle and base note” perfume raw materialsinclude, but are not limited to, eugenol, amyl cinnamic aldehyde, hexylcinnamic aldehyde, hexyl salicylate, methyl dihydro jasmonate,sandalore, veloutone, undecavertol, exaltolide/cyclopentadecanolide,zingerone, methyl cedrylone, sandela, dimethyl benzyl carbinyl butyrate,dimethyl benzyl carbinyl isobutyrate, triethyl citrate, cashmeran,phenoxy ethyl isobutyrate, iso eugenol acetate, helional, iso E super,ionone gamma methyl, pentalide, galaxolide, phenoxy ethyl propionate.

Other volatile “top note” perfume raw materials include, but are notlimited to, benzaldehyde, benzyl acetate, camphor, carvone, borneol,bornyl acetate, decyl alcohol, eucalyptol, linalool, hexyl acetate,iso-amyl acetate, thymol, carvacrol, limonene, menthol, iso-amylalcohol, phenyl ethyl alcohol, alpha pinene, alpha terpineol,citronellol, alpha thuj one, benzyl alcohol, beta gamma hexenol,dimethyl benzyl carbinol, phenyl ethyl dimethyl carbinol, adoxal, allylcyclohexane propionate, beta pinene, citral, citronellyl acetate,citronellal nitrile, dihydro myrcenol, geraniol, geranyl acetate,geranyl nitrile, hydroquinone dimethyl ether, hydroxycitronellal,linalyl acetate, phenyl acetaldehyde dimethyl acetal, phenyl propylalcohol, prenyl acetate, triplal, tetrahydrolinalool, verdox,cis-3-hexenyl acetate.

In certain embodiments, the volatile composition 24 may comprise afragrance component having a release rate ranging from 0.001 g/day to2.0 g/day. The formulation of the fragrance may comprise any suitablecombination of top, mid, and base note components.

The modulating coating 14 may be applied to at least one outer surface16 of the base material 12 and/or to the article, and may be appliedbefore or after loading of the volatile composition 24. In certainembodiments, the modulating coating 14 may penetrate into the internalstructure 20 of the base material 12 to a certain level, which may varydepending on the porosity, processing methods, or other characteristicsof the base material 12. In some embodiments, the modulating coating 14forms a continuous phase of the barrier substance 26 and the hygroscopicsubstance 28 dispersed therein when applied to at least one outersurface 16 of the base material 12 and/or the article.

The modulating coating 14 is designed to slow the release rate of thevolatile composition 24 loaded into the internal structure 20 at higherconcentration levels and accelerate the release rate of the volatilecomposition 24 at lower concentration levels in order to achieve arelatively steady release of volatile composition 24 over time. Themodulating coating 14 also serves to bind smaller, individual scentreservoirs (not shown) into a larger, three-dimensional matrix. Incertain embodiments, the modulating coating 14 may be speciallyformulated to resist the application of heat or high temperatures. Thearticle and modulating coating 14 may then be used with heat to improvethe distribution and effectiveness of the fragrance.

To explain the way that the modulating coating 14 works to have this“hold/push” effect over a range of load levels of the volatilecomposition 24, it is necessary to explain the way in which the releaserate of the volatile composition 24 is generated. The volatilecomposition 24 is loaded or absorbed into the internal structure 20 viathe pores 22 until a sufficiently high load level is achieved within theinternal structure 20 through various embodiments of loading methods,which are explained in detail below. The volatile composition 24 may beloaded or absorbed into the internal structure 20 before or after themodulating coating 14 is applied.

The initially high load level of the volatile composition 24 within theinternal structure 20 creates an internal force that causes the volatilecomposition 24 to diffuse or evaporate out of the internal structure 20as quickly as possible to a region of lower concentration. As the loadlevel of the volatile composition 24 decreases over time, the force thatcauses the diffusion or evaporation diminishes until there is no longera force remaining (i.e., an equilibrium point is reached where thevolatile composition 24 no longer diffuses or evaporates out of theinternal structure 20). The equilibrium point is usually higher than 0%concentration, which causes some of the volatile composition 24 tobecome trapped within the pores 22 of the internal structure 20.

In conventional applications, such as in U.S. Publication No.20110262377, a coating may be applied to form a layer that slows orretards the rapid release of a volatile composition at higherconcentration levels. These conventional coatings typically includesubstances that trap some of the volatile composition within the coatinglayer, which slows down the rate of release through the coating.However, because the coating only serves as a barrier or “speed bump” toslow down the rate of release of the volatile composition, the releasewill eventually stop once the concentration of volatile compositionwithin the internal structure reaches equilibrium (i.e., a level wherethere is no longer a sufficient concentration to drive the volatilecomposition through the coating layer, thus allowing some of volatilecomposition to remain trapped within the coating layer and/or within theinternal structure).

The modulating coating 14 comprises both a barrier substance 26 and ahygroscopic substance 28. In particular, in most embodiments, themodulating coating 14 comprises substances that do not chemicallyinteract with the volatile composition 24 itself. Moreover, in certainembodiments, the formulation of the modulating coating 14 is free of anyfibrous materials, such as a pulp composition.

In these embodiments, when the modulating coating 14 is applied to theouter surface 16 of the internal structure 20, at the higherconcentration levels of the volatile composition 24 within the internalstructure 20, the barrier substance 26 forms a barrier or “speed bump”to slow down the rate of release of the volatile composition 24 throughthe modulating coating 14. At these higher initial concentration levels,as illustrated in the early stage section of FIG. 1, the hygroscopicsubstance 28 does not play a role in modulating the release rate of thevolatile composition 24 (i.e., does not absorb any water into themodulating coating 14) because the concentration of the volatilecomposition 24 within the internal structure 20 is sufficiently high toforce a certain amount of the volatile composition 24 to release throughthe modulating coating 14 at a rate that effectively blocks any waterfrom being attracted into the modulating coating 14 by the hygroscopicsubstance 28.

As the concentration level of the volatile composition 24 within theinternal structure 20 slowly diminishes, as illustrated in the mid stagesection of FIG. 1, the concentration of the volatile composition 24within the internal structure 20 is still sufficiently high to continueto force some of the volatile composition 24 out of the modulatingcoating 14 at a reduced rate of release.

One hypothesis to explain the phenomenon observed in the late stage isthat because there is a lower volume of the volatile composition 24exiting the modulating coating 14, the hygroscopic substance 28 beginsto attract more water (typically in the form of water vapor) into themodulating coating 14, whereupon the water adsorbs or absorbs to thehygroscopic substance 28 and begins to displace the volatile composition24 that is trapped by the barrier substance 26 within the modulatingcoating 14. This hypothesis is illustrated in the late stage section ofFIG. 1, and is based on known physical properties of the hygroscopicsubstance 28 and the data showing higher release rates at the end of theproduct life cycle, as compared to the same product without themodulating coating 14. Once displaced, the volatile composition 24 isreleased from the modulating coating 14, thereby creating an aggregaterate of release of the volatile composition 24 that may approximate therate of release driven by the higher load level of the volatilecomposition 24 alone.

As the load level of volatile composition 24 continues to drop to alevel that can no longer drive the volatile composition 24 out of themodulating coating 14, the hygroscopic substance 28 continues to pullmore and more water into the modulating coating 14. That water continuesto displace the trapped volatile composition 24, effectively forcing thedisplaced volatile composition 24 to be released from the modulatingcoating 14. For a period of time in the late stage, the rate of releaseof the volatile composition 24 due to water displacement driven by thehygroscopic substance 28 may approximate the rate of release driven bythe higher load level of the volatile composition 24 alone and/or mayapproximate the aggregate rate of release driven by both the higher loadlevel of the volatile composition 24 and water displacement driven bythe hygroscopic substance 28. As a result, where conventional coatingsthat contain only barrier substances 26 may have stopped releasingvolatile compositions once the equilibrium point of the concentration isreached within the internal structure 20, the modulating coating 14continues to provide a relatively constant release of the volatilecomposition 24.

An alternate hypothesis to explain the phenomenon observed in the latestage is that the water that is brought into the modulating coating 14by the hygroscopic substance 28 may act to degrade the barrier substance26, which would also allow for release of the volatile composition 24trapped within the modulating coating 14 and within the internalstructure 20 of the base material 12.

In any event, the test results demonstrate that the modulating coating14 generates an improved release profile of the volatile composition 24over the aromatic life cycle of the article, depending on the porosityof the internal structure 20 of the base material 12 and the volatilitylevels of the volatile composition 24. Eventually, the concentration ofthe volatile composition 24 within the internal structure 20 and theamount trapped by the barrier substances 26 within the modulatingcoating 14 will reach such a low point that the amount of volatilecomposition 24 released on a daily basis by the modulating coating 14will eventually decline to zero.

In certain embodiments, the barrier substance 26 may comprise liquidstarch. In other embodiments, the barrier substance 26 may include butis not limited to maltodextrin (e.g. Maltrin), other dextrins, otherfilm-forming polysaccharides, other carbohydrates (mono-, di-, tri-,etc.), natural unmodified starch, modified starch, any starchappropriate for use in papermaking, as well as combinations of starchtypes, dextrin types, and combinations of starches and dextrins. Incertain embodiments, the barrier substance 26 may include but not islimited to additives such as insolubilizers, lubricants, dispersants,defoamers, crosslinkers, binders, surfactants, leveling agents, wettingagents, surface additives, rheology modifiers, non-stick agents, andother coating additives. In some embodiments, the starch may be liquid,pre-gelled, or a dry modified starch.

In certain embodiments, the hygroscopic substance 28 may comprise silica(e.g. silica nanoparticles) or a silica suspension. In otherembodiments, the hygroscopic substance 28 may include but is not limitedto other hygroscopic reagents, activated charcoal, calcium sulfate,calcium chloride, and molecular sieves, or other suitable waterabsorbing materials.

The weight ratio of the barrier substance 26 to the hygroscopicsubstance 28 may range from 99:1 to 1:99, and all ranges thereinbetween. In certain embodiments, the weight ratio of the barriersubstance 26 to the hygroscopic substance 28 may further range from25:75 to 75:25 wet weight ratio. In yet other embodiments, the weightratio of the barrier substance 26 to the hygroscopic substance 28 may beapproximately 50:50. In certain embodiments, the modulating coating 14may be formulated specifically for bonding and heat resistance. Forexample, the modulating coating 14 may be mixed with a wet weight ratioof approximately 45%-60% barrier substance 26 (e.g. liquid modifiedstarch) and approximately 40%-55% hygroscopic substance 28 (e.g. asilica suspension). In some embodiments, the modulating coating 14 maybe mixed with a ratio of 55% barrier substance 26 (e.g. liquid modifiedstarch) and 45% hygroscopic substance 28 (e.g. a silica suspension) on aweight basis. However, the ratio of the barrier substance 26 to thehygroscopic substance 28 is adjustable depending on the requiredadhesive strength and temperature resistance of a particularapplication. Generally, increasing the proportion of the barriersubstance 26 (e.g. liquid modified starch) will improve adhesion.Increases to the hygroscopic substance 28 (e.g. a silica suspension)will tend to increase thermal stability and heat resistance of themodulating coating 14. Changes to the composition of the barriersubstance 26 or hygroscopic substance 28 may also influence theproperties of the modulating coating 14. For example, using a highermolecular weight compound in the barrier substance 26, as with replacinga liquid modified starch with an un-modified starch, may yield strongeradhesion properties, even with lower concentrations of solids in thebarrier substance 26.

In certain embodiments, the particle size of the hygroscopic substance28 is determined in part by the amount of surface area needed to attractenough water to counteract the drop in release rate due to a reductionin the load level of the volatile composition 24. The hygroscopicsubstance 28 is also configured so that it will attract water vapor,rather than liquid water. As a result, the diameter of the particle sizeof the hygroscopic substance 28 may range from 0.001 μm-1 μm, and allranges therein between, and may further range from 1 nm-100 nm, whichwill attract the appropriate amount of water vapor molecules, as well asproviding a more even coating.

In certain embodiments, the hygroscopic substance 28 may have a surfacecharge range that ensures interaction with the barrier substances 26.For example, in the case of silica, the surface charge ranges from −10mV to −4000 mV, as measured by Zeta potential, which is a highly anionicpoint charge. When the silica is mixed with the liquid starch beforecoating, the liquid starch may group around the silica particles, whichmay further assist with the barrier formation within the modulatingcoating 14.

In certain embodiments, the modulating coating 14 may provide a moreconsistent release rate of the volatile composition 24. The consistency(variance) may be measured by the following formula.

Variance_((Weight-loss ratio))=First day weight-loss value/Last dayweight-loss value

The benefit of the modulating coating 14 is to reduce the variancewithin a ratio range of 1 to 20 over a life cycle of the article, whichin certain embodiments may be 30 days, but could be longer or shorter asneeded or desired.

Furthermore, in certain embodiments, use of a more concentrated versionof the volatile composition 24 in combination with the modulatingcoating 14 provides release rate improvement as disclosed herein andpresents commercial advantages over the use of the standard version ofvolatile composition 24 without modulating coating 14. The term“concentrated” used herein is intended to describe a higher amount ofolfactory-active compounds or compositions relative to othernon-volatile substances within the volatile composition 24. A moreconcentrated version of a volatile composition 24 will release into theatmosphere faster than its standard version, thus providing a higherthan desired scent intensity and character. Application of modulatingcoating 14 will moderate this faster release, resulting in a new releaserate that has the desired intensity and character. A similar performanceimprovement may be seen with the application of heat to the article 10or scent reservoirs 11. The application of heat will increase thevolatility of the volatile composition 24 relative to room temperature.This increase in volatility will lead to an increase in vapor pressure,and an increase in release rate. The modulating coating 14 can then beformulated to moderate the release rate of the volatile composition 24to maintain a long-lasting scent release and prevent disintegration ofany aggregated scent reservoirs 11 or base materials 12 that may bebonded together by the modulating coating 14. In some embodiments, themodulating coating 14 may be able to withstand constant temperatures ofup to one hundred twenty degrees Centigrade.

In certain embodiments, the loaded amount of a more concentrated versionof the volatile composition 24 into base material 12 coated withmodulating coating 14 may be less than the loaded amount of the standardversion of a volatile composition 24. This increased concentration, incombination with the optimal release rate, provides the opportunity foran increased duration of release and/or for material cost savings (byreducing the initial volatile composition load).

The base material 12 may be converted into an article, which may occurbefore or after the modulating coating 14 and/or the volatilecomposition 24 are applied.

FIG. 2 is a cross sectional view of an article 10 formed from aplurality of scent reservoirs 11 aggregated and bonded together with amodulating coating 14. The scent reservoirs 11 are comprised of a basematerial 12 that may be infused with a volatile composition 24 (notshown) either before or after the application of the modulating coating14. In certain embodiments, the scent reservoirs 11 may be comprised ofthe trimmings of larger pieces that are to be sold as individualfragrance-release devices. For example, in some embodiments, the scentreservoirs 11 may be the end trimmings of tightly wound paper sticks,which are to be processed and sold separately. In other embodiments, thescent reservoirs 11 may be any type of absorbent or porous material thatmay be infused with a volatile composition 24 including, but not limitedto, wood chips, extruded pulp, fiber bundles, and/or ceramic chunks. Anysize of scent reservoir 11 may be bonded together to make an aggregatearticle 10.

The scent reservoirs 11 may be formed into an aggregate article 10 bybonding them to one another with the modulating coating 14. In someembodiments, the modulating coating 14 may be specifically formulatedfor a particular purpose. Typically, as noted above, the bondingmodulating coating 14 will be comprised of a mixture of a barriersubstance 26 and a hygroscopic substance 28. In some cases, it may bedesirable to formulate the modulating coating 14 so as to resist heat orhigh temperatures to allow the aggregate article 10 to be used with awarmer to improve the release and distribution of the fragrance from thebase material 12. For example, the modulating coating 14 may be mixedwith a ratio of 55% barrier substance 26 (e.g. liquid modified starch)and 45% hygroscopic substance 28 (e.g. a silica suspension) on a weightbasis. However, the ratio of the barrier substance 26 to the hygroscopicsubstance 28 is adjustable depending on the required adhesive strengthand temperature resistance of a particular application.

To manufacture an aggregate article 10 from a plurality of scentreservoirs 11, a desired number of scent reservoirs 11 are mixed withthe adhesive modulating coating 14. In some embodiments, the ratio ofscent reservoirs 11 to modulating coating 14 may be three to one on aweight basis. Said differently and by way of example, the mixture ofscent reservoirs 11 and modulating coating 14 may be comprised of 75%scent reservoirs 11 and 25% modulating coating 14 by weight. The ratioof scent reservoirs 11 to modulating coating 14 may be adjusted asnecessary for any particular application, but generally may fall withinthe range of 90% scent reservoirs 11 to 10% modulating coating 14 and10% scent reservoirs 11 to 90% modulating coating 14 based on weight.The particular ratio of scent reservoirs 11 to modulating coating 14 maybe based on, among other things, the shape, size, and/or packing factorof the scent reservoirs 11, and/or the strength, permeability, and/orheat tolerance of the modulating coating 14. In certain embodiments, itmay be preferable to infuse the scent reservoirs 11 with a volatilecomposition 24 and/or coloring agent prior to production of theaggregate article 10. However, it is also possible to infuse theaggregate article 10 with color and fragrance after the production ofthe aggregate article 10 has been completed. For instance, in certainembodiments, the fragrance may be added to an aggregate article 10 witha dropper, by dipping the aggregate article 10, passing it through afragrance curtain, infusing fragrance under vacuum, or any othersuitable method for infusing or introducing a fragrance or volatilecomposition 24 into the aggregate article 10.

After the mixture of scent reservoirs 11 and modulating coating 14 hasbeen prepared and well mixed to ensure even and complete coating of thescent reservoirs 11, the mixture may be deposited in a mold that definesthe desired end shape of the aggregate article 10. The mixture of scentreservoirs 11 and modulating coating 14 may be pressed or compacted intothe mold to ensure complete filling and proper packing of the scentreservoir 11 and modulating coating 14 mixture. As used herein,compaction of the scent reservoir 11 and modulating coating 14 mixturedoes not necessarily require or involve the distortion or deformation ofthe scent reservoirs 11. Rather, compacting or pressing the mixture ofscent reservoirs 11 and modulating coating 14 may be adjusted to achieveremoval of excess modulating coating 14, to influence packing factor ofthe scent reservoirs 11, and to control the size of the voids 13 betweenthe scent reservoirs 11. The mold (not shown) may, in some embodiments,be a wire mold or otherwise perforated to allow for air and excessmodulating coating 14 to escape the mold during production of theaggregate article 10. Perforations of the mold also facilitate drying,as moisture and/or vapors may more easily escape the mold.

Once the mixture of scent reservoirs 11 and modulating coating 14 hasbeen placed into a mold and compacted as necessary, the mold containingthe mixture must be allowed to dry. Drying may be accomplished inambient air. However, in certain embodiments, it may be preferable todry the mixture using heat, ovens, heat tunnels, fans, or microwaves tospeed the drying process. Once the mixture of scent reservoirs 11 andmodulating coating 14 has dried, the aggregate article 10 may be removedfrom the mold.

The combination of barrier substance 26 and hygroscopic substance 28 maycomprise 1% to 20% of the total composition by weight of the driedmodulating coating 14.

The aggregate article 10 may be adapted for use as a fragrance-releasedevice in any number of applications. The geometry, sizing, materials,and type of volatile composition 24 used in the scent reservoirs 11 maybe chosen specifically for an aggregate article 10, which is to be usedin ambient air, on a table top, as a hanging fragrance-release device,or in combination with a heater or forced air assist. Similarly, theformulation, composition, and amount of modulating coating 14 used inthe production of the aggregate article 10 may be adjusted or modifiedas required for any of the aforementioned uses.

The use of an aggregate article 10 made up of a plurality of scentreservoirs 11 may have additional functionality over the use of anarticle constructed from a single scent reservoir 11 or a similar numberof loose, unbonded scent reservoirs 11, even when the same modulatingcoating 14 is applied. An aggregate article 10 comprising a plurality ofscent reservoirs 11 that are bonded together using a modulating coating14 may offer additional methods for regulating or controlling therelease of the volatile composition 24 from the aggregate article 10. Asdescribed above, the modulating coating 14 may regulate the rate ofrelease of the volatile composition 24 at high concentrations by slowingdiffusion and also increasing the rate of diffusion when theconcentration of volatile compositions 24 is lower (see FIG. 1 andassociated description). However, an aggregate article 10 may introducea second, geometry based regulation of the release of volatilecompositions 24 from the aggregate article 10 and its associated scentreservoirs 11.

The aggregate article 10 compacts a plurality of scent reservoirs 11into an aggregate mass. If the scent reservoirs 11 were left in as anagglomeration of loose, individual parts, the volatile compositions 24held in the base material 12 of the scent reservoirs 11 would diffusethrough the entire surface area of the scent reservoirs 11. However,when the scent reservoirs 11 are compacted into a matrix to create theaggregate article 10, a number of the scent reservoirs 11 will bepositioned either partially or fully within the interior of theaggregate article 10. The compaction of the scent reservoirs 11 into anaggregate article 10 reduces the proportion of surface area to thevolume of the scent reservoirs 11 and the amount of volatilecompositions 24 held within the scent reservoirs 11.

Still referring to FIG. 2, the aggregate article 10 has a number ofvoids 13 between the compacted and bonded scent reservoirs 11. Thesevoids 13 may be entirely closed to the ambient air, or they may bepartially or fully exposed depending upon the location of the voids 13and the arrangement of the scent reservoirs 11. In certain embodiments,a number of voids 13 may be linked or connected together such that avoid 13 that is relatively far from the surface of the aggregate article10 may have a passage for transfer of vapors and/or gases from theinterior void 13 to the exterior surface of the aggregate article 10.This path, however, may be constricted, circuitous, or tortuous, slowingthe exchange of gases or vapors from the inner portions of the aggregatearticle 10 to the surface. This constricted pathway for the volatilecompositions 24 provides an additional mechanism for regulating orotherwise controlling the release of volatile compositions 24 into thesurrounding environment.

Internal voids 13 in the aggregate article 10 may also control therelease of volatile compositions 24 when they are closed off from theexterior surface of the aggregate article 10. Closed off internal voids13, which do not have direct gas exchange with the external environment,will contain volatile compositions 24, which diffuse into the void 13from the surrounding scent reservoirs 11. Initially, when the aggregatearticle 10 is new or relatively new, the scent reservoirs 11 will haveapproximately equal concentrations of volatile compositions 24. Thediffusion from adjacent scent reservoirs 11 into the void 13 will beapproximately equal and will continue until it reaches equilibrium. Atthis point, adjacent scent reservoirs 11 will absorb volatilecompositions 24 from the void 13 at approximately the same rate as theyrelease volatile compositions 24 into the void 13. At some point, thescent reservoirs 11 that are relatively closer to the surface of theaggregate article 10 will have lost a portion of their volatilecompositions 24 to the surrounding environment. The scent reservoirs 11that are relatively closer to the surface may share an internal void 13with a scent reservoir 11 that is not directly exposed to the surface.The diffusion of volatile compositions 24 through the internal void 13will become unbalanced, leading to a net transfer of volatilecompositions 24 from a relatively more interior scent reservoir 11 tothe relatively more exposed scent reservoir 11 through the internal void13. This mechanism tends to delay the release of volatile compositions24 from less exposed scent reservoirs 11 because the volatilecompositions 24 must diffuse over a greater distance to the surface ofthe aggregate article 10 and must pass through multiple layers of themodulating coating 14. This multi-boundary control provides for longerlasting, more controlled release of volatile compositions 24 from thescent reservoirs 11.

FIGS. 9 and 10 are graphs that generally compare the cumulative releaseof a fragrance over time compared between loose scent reservoirs 11 andcompacted or aggregate article 10, both in ambient and heatedconditions. As shown, heated scent reservoirs 11 and aggregate articles10 release a greater amount of fragrance than scent reservoirs 11 andaggregate articles 10 exposed to ambient conditions. However, under thesame conditions, an aggregate article 10 releases fragrance moregradually than loose scent reservoirs 11. FIGS. 9 and 10 also providehedonic ratings for the loose scent reservoirs 11 and a compacted oraggregate article 10 when heated. The hedonic rating is an indication ofthe impact of the scent released by the loose scent reservoirs 11 andaggregate article 10. The hedonic rating scale evaluates the scent onthe following scale: −4 (extremely weak), −3 (very weak), −2 (moderatelyweak), −1 (slightly weak), 0 (just right), +1 (slightly strong), +2(moderately strong), +3 (very strong), +4 (extremely strong). Thegeneral protocol for evaluating hedonic impact is as follows: (i) placetest product in testing room (10′ (w)×14′ (l)×9′ (h)) one hour beforeevaluation; (ii) direct panelists to enter the testing room and stand ina marked area approximately eight feet from test product; and (iii)instruct panelists to evaluate hedonic impact based on fragranceintensity.

FIGS. 3-8 are photographic depictions of different shapes of anaggregate article 10 comprising a plurality of scent reservoirs 11. Eachscent reservoir 11 may be comprised of a base material 12, which isinfused with volatile compositions 24 (not shown) and coated with amoderating coating 14 (not shown). Any number of shapes may be madeusing the previously-described manufacturing method. Some exemplary,non-limiting shapes are shown in FIGS. 3-8, including spherical (FIG.3), pyramidal (FIG. 4), heart-shaped (FIG. 5), tree-shaped (FIG. 6), astick pile (FIG. 7), toroidal, and cubic (FIG. 8). Additional variationsin shape, size, and level of compaction are possible. In certainembodiments, as shown in FIG. 6, the scent reservoirs 11 and resultingaggregate article 10 may be dyed or otherwise pigmented to produce anydesired color of the final product. Also, in some embodiments, as shownin FIG. 7, the scent reservoirs 11 may be relatively larger or smaller.In FIG. 7, the scent reservoirs 11 are large enough that they may besold individually as fragrance-release devices, or they may be used asconstituents in an aggregate article 10.

The different shapes of the aggregate articles 10 shown in FIGS. 3-8 mayserve to provide an aesthetically pleasing aggregate article 10.However, differing shapes of the aggregate article 10 also provide fordifferent function of the aggregate article 10 and provide another meansof controlling the release of volatile compositions 24 from the scentreservoirs 11 of the aggregate article 10. Adjustments or alterations tothe overall shape of the aggregate article 10 may influence the rate ofrelease of the volatile compositions 24 in a number of ways. Forexample, changes to the shape of the aggregate article 10 may influencethe ratio of surface area to volume or the ratio of exposed scentreservoirs 11 to interior scent reservoirs 11. The shape of theaggregate article 10 may also affect the interaction of the aggregatearticle 10 with other devices, such as fans, forced air blowers, orheaters. For example, the efficiency of a fan or forced air blower onthe aggregate article 10 will increase or decrease depending on whetherthe shape of the aggregate article 10 encourages efficient contactbetween the surfaces of the scent reservoirs 11 and the air current. Incertain embodiments, the aggregate article 10 may be used in combinationwith a heater to warm the aggregate article 10 and its constituent scentreservoirs 11. The shape of the aggregate article 10 will determine theamount of contact area between the heater and the aggregate article 10,and also the average distance of the scent reservoirs 11 from the heatsource, regardless of whether or not they are in direct contact.

FIG. 11 is a graph showing a comparison of cumulative fragrance releasefor differently shaped aggregate articles 10 and loose scent reservoirs11. As shown, a short and wide aggregate article 10 releases itsvolatile compositions 24 more quickly than a medium or tall and thinaggregate article 10. The short and wide aggregate article 10 onlyslightly outperforms the loose scent reservoirs 11 over time in a heatedcondition. One reason for this difference in performance may be that theshort and wide aggregate article 10 has a greater area of contact withthe heater, giving a higher level of heat transfer. Furthermore, theindividual scent reservoirs 11 are, on average, closer to the heatsource. By contrast, the tall, thin aggregate article 10 may have asmaller contact area with the heat source, and the average distance ofthe scent reservoirs 11 is greater. The result is that fewer scentreservoirs 11 are at a higher temperature and will more release thevolatile compositions 24 at a slower rate.

As discussed above, an aggregate article 10 that is to be used with aheat source should comprise a modulating coating 14, which is formulatedto tolerate temperatures that the aggregate article 10 is likely toencounter with a heating device, such as a wax warmer. The modulatingcoating 14 must have enough heat tolerance to not only maintain functionas a moderator of the release of volatile compositions 24, but it mustalso maintain its bonding properties at elevated temperatures to preventdisintegration of the aggregate article 10 and its matrix of scentreservoirs 11. Unintended changes to the shape of the aggregate article10 may lead to uncontrolled release of the volatile compositions 24 anda potential deterioration of performance.

The modulating coating 14 may be applied to the base material 12 beforeor after application of the volatile composition 24. For example, themodulating coating 14 may be applied when the base material 12 is in atwo-dimensional form via conventional two-dimensional coating methodstypically used for treating two-dimensional sheets of material, such aspaper. These methods include but are not limited to at least one ofgravure printing, offset printing, flexographic printing, rod coating,blade coating, curtain coating, or other suitable coating methods. Inthese two-dimensional embodiments, the modulating coating 14 may beapplied to the base material 12 when the base material 12 is in a singletwo-dimensional layer, after which the base material 12 layers areassembled together to form the article 10. In other two-dimensionalembodiments, the base material 12 may be arranged into the layeredmaterial prior to application of the modulating coating 14 so that themodulating coating 14 is only applied to the outermost surface 16 of thetop layer of the base material 12 (although the modulating coating 14may penetrate to a certain depth within the article 10).

In other embodiments, the modulating coating 14 may be applied to themold containing scent reservoirs 11 that will become thethree-dimensional article 10 via an infusion method with the add-oninfusion ranging from 1% to 20% by dry weight, and, in certainembodiments, may further range from 1% to 10% by dry weight.

In certain embodiments, the modulating coating 14 may be applied to thebase material 12 or scent reservoirs 11 via pouring and mixing. In yetother embodiments, the modulating coating 14 may be applied to the basematerial 12 or scent reservoirs 11 via spray treatment.

The volatile composition 24 may be applied to the base material 12before or after application of the modulating coating 14, as describedabove. For example, the volatile composition 24 may be applied byplacing the base material 12 and/or the scent reservoirs 11 in intimatecontact with the volatile composition 24 for a period of time. Thevolatile composition 24 may be in any physical state, such as liquid,solid, gel, or gas. For convenience, a liquid volatile composition 24 isdescribed, but this is not intended to be limiting. The interaction timemay depend on the concentration or type of volatile composition 24 beingapplied to the base material 12 and/or the scent reservoirs 11, and/orhow strong or intense of a volatile composition 24 release desired,and/or the type of base material 12. In certain embodiments, the scentreservoirs 11 may be infused with a liquid fragrance composition. Theamount of liquid fragrance composition and the saturation time forinfusing the scent reservoirs 11 and/or aggregate article 10 with theliquid fragrance composition will vary depending on the particularparameters of the application. For example, the size of the scentreservoirs 11, the size of the aggregate article 10, the characteristicsof the liquid fragrance (e.g. viscosity, concentration, compatibilitywith the material of the scent reservoirs 11 and/or aggregate article10, and strength of scent), the holding capacity of the scent reservoirs11 and/or aggregate article 10, and the expected service life of thescent reservoirs 11 and/or aggregate article 10 will influence theamount of liquid fragrance composition infused and the necessarysaturation time. The base material 12 and/or scent reservoirs 11 may bepre-treated prior to exposure to the volatile composition 24. Forexample, the base material 12 and/or scent reservoirs 11 may be placedin a drying oven to remove any residual moisture. Further method stepscomprise pressure treating and/or vacuum treating the base material 12and/or scent reservoirs 11. After treatment, the base material 12 and/orscent reservoirs 11 may be dried, for example by rubbing or patting dry,and/or by other methods known for drying a surface, and/or may be leftto air dry. Drying steps may be used before or after other stepsdescribed herein.

In some embodiments, a method for applying the volatile composition 24to the base material 12 and/or scent reservoirs 11 comprises combiningthe volatile composition 24 and the base material 12 and/or scentreservoirs 11 in a container and applying a pressure above atmosphericpressure on the volatile composition 24 and base material 12 and/orscent reservoirs 11. Pressure may be applied in a range from about 1 psito about 40 psi, from about 5 psi to about 30 psi, or from about 10 psito about 20 psi, at about 5 psi, at about 10 psi, at about 15 psi, atabout 20 psi, at about 25 psi, at about 30 psi, at about 35 psi, atabout 40 psi, and/or at pressures therein between. The pressure may beapplied for a period of time from about 1 minute to about 10 hours, forabout 30 minutes, for about 1 hour, for about 2 hours, for about 3hours, for about 4 hours, for about 5 hours for about 6 hours, for about7 hours, for about 8 hours, for about 9 hours, for about 10 hours, orlonger if needed to apply sufficient amounts of the volatile composition24 to the base material 12 and/or scent reservoirs 11 to achieve adesired load of the volatile composition 24 to the base material 12and/or scent reservoirs 11 or release of the volatile composition 24from the base material 12 and/or scent reservoirs 11. Appropriatepressures and times for a particular embodiment can be determined by oneskilled in the art based on the identities and characteristics of theparticular volatile composition 24 and base material 12 and/or scentreservoirs 11.

In certain embodiments, a method for applying the volatile composition24 comprises combining the volatile composition 24 and base material 12and/or scent reservoirs 11 in a container and applying a vacuum belowatmospheric pressure to the volatile composition 24 and the basematerial 12 and/or scent reservoirs 11. Vacuum may be applied in a rangefrom 0.001 mm Hg to about 700 mm Hg, or from about 5 Kpa to about 35kPa, from about 10 Kpa to about 25 kPa, from about 20 Kpa to about 30kPa, from about 15 Kpa to about 25 kPa, from about 25 Kpa to about 30kPa, at about 5 kPa, at about 6 kPa, at about 7 kPa, at about 8 kPa, atabout 9 kPa, at about 10 kPa, at about 15 kPa, at about 16 kPa, at about17 kPa, at about 18 kPa, at about 19 kPa, at about 20 kPa, at about 22kPa, at about 24 kPa, at about 26 kPa, at about 28 kPa, at about 30 kPa,and vacuums therein between. The vacuum may be applied for a period oftime from about 1 minute to about 10 hours, for about 30 minutes, forabout 1 hour, for about 2 hours, for about 3 hours, for about 4 hours,for about 5 hours for about 6 hours, for about 7 hours, for about 8hours, for about 9 hours, for about 10 hours, or longer if needed toapply sufficient amounts of the volatile composition 24 to the basematerial 12 and/or scent reservoirs 11 to achieve a desired load of thevolatile composition 24 to the base material 12 and/or scent reservoirs11 or release of the volatile composition 24 from the base material 12and/or scent reservoirs 11.

In yet other embodiments, the method may comprise pressure and vacuumsteps. The volatile composition 24 and the base material 12 and/or scentreservoirs 11 may be combined and undergo vacuum treatment and pressuretreatment, in no particular order. For example, the volatile composition24 and the base material 12 and/or scent reservoirs 11 may be combinedin a container in an air-tight apparatus and a vacuum of 20 mm Hg to 80mm Hg may be applied for about 1 minute to 10 hours. Pressure treatmentof 1 psi to 40 psi may be applied for about 1 minute to about 10 hoursand the time and amount of vacuum or pressure treatment may vary anddepend upon the amount of volatile composition 24 to be loaded in thebase material 12 and/or scent reservoirs 11, the type of base material12 used, the intended use of the scent reservoirs 11, and othercharacteristics of the scent reservoirs 11.

In certain embodiments, the base material 12 and/or scent reservoirs 11may be pre-treated with colorants, followed by treatment with themodulating coating 14. Colorants may include natural and synthetic dyes,water-resistant dyes, oil-resistant dyes, and combinations of water- andoil-resistant dyes. Colorants may be selected based on the compositionof the base material 12 or scent reservoirs 11, and is well within theskill of those in the art. Suitable water-resistant colorants includeoil soluble colorants and wax soluble colorants. Examples of oil solublecolorants include Pylakrome Dark Green and Pylakrome Red (Pylam ProductsCompany, Tempe Ariz.). Suitable oil-resistant colorants include watersoluble colorants. Examples of water soluble colorants include FD&C BlueNo. 1 and Carmine (Sensient, St. Louis, Mo.). A Lake type dye may alsobe used. Examples of Lake dyes are Cartasol Blue KRL-NA LIQ and CartasolYellow KGL LIQ (Clariant Corporation, Charlotte, N.C.). Pigments mayalso be used in coloring the base material 12 and may be added during orafter the manufacture of the base material 12 and/or scent reservoirs11. Such coloring or dying methods are known to those skilled in theart, and any suitable dyes, pigments, or colorants are contemplated bythe present invention. Colorants may be used to affect the overallsurface charge of the silica or other hygroscopic substance 28 toenhance the interaction with the coating.

EXAMPLES Example 1 Synthesis of the Adhesive/Modulating Coating for 3DAggregate Article Manufacture

The composition for the adhesive/modulating coating 14 is made by mixingtwo components, a modified starch and a silica suspension. One exampleof a modified starch is liquid starch (P30L) from Grain Processing(Muscatine, Iowa). Other liquid starches, pre-gelled starches, or drymodified starches can be used with the proper make-down and/or cookingequipment. One example of a silica suspension is Snowtex®-O from NissanChemical America Corporation (Houston, Tex.). Other silica suspensionsmay also be adequate. The adhesive/modulating coating mixture is made bythoroughly mixing P30L with Snowtex®-O in the ratio 55% P30L and 45%Snowtex®-O (wt/wt). This ratio is adjustable depending on the neededadhesive strength for the shape being made.

Example 2 Manufacture of 3D Aggregate Article

Aggregate article 10 is made by gluing enough loose scent reservoirs 11to form the desired shape and size; the glue used is theadhesive/modulating coating 14 described in Example 1. One example of aloose scent reservoir 11 is a paper media comprised of cut ends fromspiral wound paper stick manufacturing. Other absorbent material insmall piece form may also be used. Scent reservoirs 11 may be pre-dyedto the desired color. The shape of the aggregate article 10 is enabledby a mold, which may consist of a wire mold or other constraining devicethat allows the scent reservoirs 11 to be formed into the desired shape.Molds with a multitude of openings (smaller than the size of the scentreservoirs 11) are preferred, since they allow for more efficientdrying. Drying methods may include the use of ovens, heat tunnels, fan,ambient air, microwaves, etc. The manufacture process starts with mixingthe loose scent reservoirs 11 with the adhesive/modulating coating 14mixture at a ratio of 75% to 25% (wt/wt). The ratio may be adjusted tomeet the desired property; and this ratio range may be 10% to 90%(wt/wt) and 90% to 10% (wt/wt). The mixture of loose scent reservoirs 11and adhesive/modulating coating 14 is placed in a mold and press inplace firmly to fill any voids in the mold (except for the voids betweenscent reservoirs 11 based on geometry). The filled-mold in an oven/heattunnel for accelerated drying, or allowed to dry at ambient conditionsor under a fan overnight. Once dried, the formed aggregate article 10 ispopped out of the mold. Adding fragrance to the aggregate article 10 maybe done by (i) carefully adding a specified amount (15% (wt/wt) in oneembodiment) to the aggregate article 10 with a dropper, (ii) quicklydipping the aggregate article 10 into the fragrance, (iii) running theaggregate article 10 through a fragrance curtain (similar to curtaincoating), (iv) completely infusing the aggregate article 10 in fragranceunder vacuum or (v) any other suitable method. The amount of fragranceloaded can be varied to achieve the appropriate hedonic effect for thesize and shape of aggregate article 10.

Example 3 Weight-Loss Study to Evaluate Fragrance Release

The rate and duration of fragrance release by a aggregate article 10(and other product formats) on a commercial wax warmer were evaluated bymeasuring the weight-loss over time. Commercially available wax warmerswere purchased and used without modification. The aggregate article 10containing fragrance is placed in the wax warmer holder; and the mass ofthe holder and aggregate article 10 with fragrance is recorded. The testsample containing holder is placed on the wax warmer, and the wax warmeris turned on. At specified time, the mass of the holder with test sampleis recorded. In parallel, the hedonic impact of the fragrance releasedis evaluated at a specified time by a simple rating scale by a humansubject. The rating scale is: −4 (extremely weak), −3 (very weak), −2(moderately weak), −1 (slightly weak), 0 (just right), +1 (slightlystrong), +2 (moderately strong), +3 (very strong), +4 (extremelystrong).

FIG. 9 is a plot showing cumulative release of Fragrance 1 over time.The results show the aggregate article 10 format in wax warmer has abetter fragrance release profile and hedonic impact than the loose scentreservoirs 11 format in wax warmer. The implication is an even, longerduration of fragrance release for the aggregate article 10.

FIG. 10 is a plot showing cumulative release of Fragrance 2 over time.The results show the aggregate article 10 format in wax warmer has abetter fragrance release profile and hedonic impact than the loose scentreservoirs 11 format in wax warmer. The implication is an even, longerduration of fragrance release for the aggregate article 10.

FIG. 11 is a plot showing cumulative release of Fragrance 2 over time.The results show the impact of aggregate article 10 shape and size onfragrance release. Increasing size, specifically increasing contact areato the heated surface of a wax warmer allows for more fragrance release.Increasing distance (height of aggregate article 10) from the heatedsurface of a wax warmer decreases the initial fragrance release, butthis allows for increased duration of fragrance release.

Each of the above noted test runs was undertaken using identicalfragrances, amounts of fragrance, scent reservoirs 11 (whether in looseor aggregate article 10 format), and applications of heat. The loosescent reservoirs 11 and aggregate articles 10 used their respectiveappropriate formulations and mixtures of the modulating coating 14 asnecessary to achieve the required bonding characteristics for testing.

1. A bonding modulating coating configured to provide an improvedrelease profile of a volatile composition from a scent reservoir,wherein the bonding modulating coating comprises: a barrier substanceconfigured to hinder a release of the volatile composition through thebonding modulating coating; and a hygroscopic substance configured tofacilitate the release of the volatile composition through the bondingmodulating coating; wherein the barrier substance and the hygroscopicsubstance are mixed in a proportion to provide bonding between adjacentscent reservoirs.
 2. The bonding modulating coating of claim 1, whereinthe hygroscopic substance is configured to facilitate the release of thevolatile composition through the bonding modulating coating byattracting water molecules into the bonding modulating coating todisplace the volatile composition trapped by the barrier substancewithin the bonding modulating coating.
 3. The bonding modulating coatingof claim 1, wherein the hygroscopic substance comprises a silicasuspension and the barrier substance comprises liquid starch. 4.(canceled)
 5. The bonding modulating coating of claim 1, wherein thebonding modulating coating is configured to resist temperatures higherthan ambient and to resist direct heating.
 6. (canceled)
 7. The bondingmodulating coating of claim 5, wherein a wet weight ratio of the barriersubstance to the hygroscopic substance is approximately 25:75.
 8. Thebonding modulating coating of claim 5, wherein a wet weight ratio of thebarrier substance to the hygroscopic substance is approximately 75:25.9. The bonding modulating coating of claim 5, wherein the bondingmodulating coating comprises approximately 45 to 60 percent barriersubstance by wet weight.
 10. The bonding modulating coating of claim 5,wherein the bonding modulating coating comprises approximately 40 to 55percent hygroscopic substance by wet weight.
 11. The bonding modulatingcoating of claim 5, wherein a wet weight ratio of the barrier substanceto the hygroscopic substance is approximately 55:45.
 12. The bondingmodulating coating of claim 1, wherein a particle size of thehygroscopic substance ranges from 0.001 μm-1 μm.
 13. An aggregatearticle comprising: a plurality of scent reservoirs comprising aninternal structure; a volatile composition, wherein at least some of thevolatile composition is located in the internal structure; and amodulating coating substantially covering at least one of the pluralityof scent reservoirs, wherein the modulating coating comprises a barriersubstance and a hygroscopic substance; and wherein the modulatingcoating is configured to bond the plurality of scent reservoirs into athree-dimensional matrix.
 14. The aggregate article of claim 13, whereinthe hygroscopic substance comprises a silica suspension and the barriersubstance comprises liquid starch.
 15. (canceled)
 16. The aggregatearticle of claim 13, wherein the modulating coating is configured toresist temperatures higher than ambient and to resist direct heating.17. (canceled)
 18. The aggregate article of claim 16, wherein a wetweight ratio of the barrier substance to the hygroscopic substance is atleast one of approximately 75:25 and approximately 25:75.
 19. (canceled)20. The aggregate article of claim 16, wherein the modulating coatingcomprises approximately 45 to 60 percent barrier substance by wetweight.
 21. The aggregate article of claim 16, wherein the modulatingcoating comprises approximately 40 to 55 percent hygroscopic substanceby wet weight.
 22. The aggregate article of claim 16, wherein a wetweight ratio of the barrier substance to the hygroscopic substance isapproximately 55:45.
 23. The aggregate article of claim 13, wherein aparticle size of the hygroscopic substance ranges from 0.001 μm-1 μm.24. The aggregate article of claim 13, wherein: the plurality of scentreservoirs comprises at least one scent reservoir selected from thegroup consisting of wound paper, extruded pulp, wood chips, fiberbundles, and ceramic chunks; at least some of the volatile compositionis located within the modulating coating; and the modulating coatingfurther comprises water that is absorbed or adsorbed to the hygroscopicsubstance.
 25. (canceled)
 26. An aggregate article comprising: aplurality of scent reservoirs comprising an internal structurecomprising pores; a volatile composition, wherein at least some of thevolatile composition is located in the pores; a modulating coatingdistributed on exterior surfaces of the plurality of scent reservoirs;wherein the modulating coating is formulated to provide a heat resistantbond between the plurality of scent reservoirs; and wherein themodulating coating regulates a release rate of the volatile compositionlocated in the pores. 27-31. (canceled)